CN204967678U - High -speed brushless DC motor controlling means - Google Patents

Abstract

The utility model relates to a high -speed brushless DC motor controlling means, including MCU micro controller unit, MOS pipe three -phase bridge unit with the three hall sensor in locating the brushless DC motor stator, MCU micro controller unit's output links to each other with the input of MOS pipe three -phase bridge unit, and the output of MOS pipe three -phase bridge unit links to each other with brushless DC motor's stator coil's input respectively, and three hall sensor's output is continuous with MCU micro controller unit's input respectively. The utility model discloses leave out RC filter circuit and MOS drive circuit, reduced the feedback and postpone and the control lag, effectively solved the phase lag problem to can take into account the just reversal of motor, guarantee the high -speed operation of motor, improve stability and production yield, reduce cost.

Description

A high-speed brushless DC motor control device

technical field

The utility model relates to a motor, in particular to a high-speed brushless DC motor control device.

Background technique

At present, in the three-phase brushless DC motor controller, the control scheme with Hall position feedback is commonly used. The relative position angle of the stator and the Hall sensor is determined, and three Hall sensors are installed in the stator. The controller generally includes a microcontroller, a MOS drive circuit, a drive bridge composed of six MOS tubes, and an RC filter circuit. The microcontroller, MOS drive circuit, and MOS tube drive bridge are connected in sequence. The three output terminals of the MOS tube drive bridge are respectively It is connected with the three stator coils of the brushless DC motor, and the output terminals of the three Hall sensors installed in the stator are connected with the input terminals of the microcontroller through an RC filter circuit. When the rotor magnetic pole passes near the Hall sensor, the Hall sensor will send a high (low) level signal, and the microcontroller reads the signal combination of the three Hall sensors processed by the RC filter circuit through the input IO port. Judging the current position of the rotor, the next correct energization sequence of the stator coil is obtained, and then the microcontroller outputs the corresponding PWM signal to the MOS drive circuit, and then processed by the MOS tube drive bridge, the output control signal makes the corresponding winding of the stator coil Power is applied so that the rotor continues to run smoothly.

The traditional control scheme is a process of detecting first and then judging, which will inevitably cause output lag. At the same time, due to the hysteresis of the magnetic detection and signal output of the Hall element itself, and in order to eliminate the external interference of the circuit or the internal clutter signal, a filter capacitor needs to be added to the Hall level conversion circuit, and the existence of the capacitor will also cause the Hall signal. Although the output hysteresis can reduce the capacitance and improve the hysteresis, it will cause the Hall signal interference to be eliminated, which is not advisable. In addition, during forward rotation, the problem of phase lag can also be improved by correcting the installation angle of the Hall sensor relative to the stator, but if the motor reverses, the lag will be more serious, so this correction method cannot take into account both forward and reverse rotation of the motor state. Therefore, due to the existence of the hysteresis effect, the phase lag of the back EMF of the brushless DC motor with Hall control is delayed, the output efficiency is reduced, and the high-speed operation is limited.

Generally speaking, the traditional brushless DC motor controller has the following disadvantages: it needs to be connected with an RC filter circuit, which causes a delay in signal transmission, making the controller unable to track the latest control state in real time, resulting in a decrease in control efficiency and inability to operate at high speeds; peripheral circuits It is complex and requires a complex power tube drive circuit, which affects the consistency and control performance of the overall circuit; more components are used, resulting in a low enough defective rate in mass production and high costs.

Contents of the invention

The utility model mainly solves the technical problems that the original brushless DC motor controller with Hall control has an RC filter circuit, which causes the phase lag of the back electromotive force of the motor, reduces the output efficiency, and limits high-speed operation; provides a high-speed brushless DC motor The control device eliminates the RC filter circuit, reduces feedback delay and control delay, and can take into account the forward and reverse rotation of the motor to control the high-speed operation of the motor.

The utility model simultaneously solves the problem of the original brushless DC motor controller with Hall control, which has both an RC filter circuit and a MOS drive circuit. The peripheral circuit is complex, and many components are used, which affects the consistency and control performance of the overall circuit. , resulting in the technical problems that the mass production defect rate is not low enough and the cost is high; a high-speed brushless DC motor control device is provided, which requires neither an RC filter circuit nor a MOS drive circuit, which simplifies the circuit and greatly reduces external components. Reduce, improve stability and production yield, and also reduce costs.

The above-mentioned technical problems of the utility model are mainly solved by the following technical solutions: the utility model comprises an MCU microcontroller unit, a MOS tube three-phase bridge unit and three Hall sensors arranged in the brushless DC motor stator, The output end of the MCU microcontroller unit is connected to the input end of the MOS tube three-phase bridge unit, and the output end of the MOS tube three-phase bridge unit is connected to the input end of the stator coil of the brushless DC motor respectively. The output ends of the Hall sensors are respectively connected to the input ends of the MCU microcontroller unit. The Hall sensor detects the rotor position of the brushless DC motor in real time and sends it to the MCU microcontroller unit. The MCU microcontroller unit reads the current Hall value, analyzes and processes it, filters the Hall feedback signal, and then outputs the power The control signal is sent to the MOS tube three-phase bridge unit, and the MOS tube three-phase bridge unit controls the energization sequence of the stator coils of the brushless DC motor to control the operation of the brushless DC motor. In an environment with stronger Hall interference, the filter coefficient can be changed without changing the hardware circuit to ensure that the Hall signal is correct. The technical solution omits the RC filter circuit, reduces the feedback delay and control delay, and can take into account the positive and negative rotation of the motor, thereby controlling the high-speed operation of the motor. At the same time, the original MOS drive circuit is also omitted, the circuit is simplified, the external components are greatly reduced, the stability and production yield are improved, and the cost is also reduced.

As preferably, the MCU microcontroller unit includes a single-chip microcomputer U with a built-in MOS drive circuit. The single-chip microcomputer U has six output terminals of PWM0 pins, PWM1 pins, PWM2 pins, PWM3 pins, PWM4 pins and PWM5 pins. The MOS The tube three-phase bridge unit has six MOS tubes, and the PWM0 pin, PWM1 pin, PWM2 pin, PWM3 pin, PWM4 pin and PWM5 pin of the microcontroller U are respectively connected to the bases of the six MOS tubes. The six power control output ends of the single-chip microcomputer U control the turn-on or cut-off of the six MOS tubes, thereby controlling the energization sequence of the stator coils of the brushless DC motor. The circuit is simple, the reliability is improved, and the cost is also reduced.

Preferably, the MOS transistor three-phase bridge unit includes MOS transistor Q0, MOS transistor Q1, MOS transistor Q2, MOS transistor Q3, MOS transistor Q4 and MOS transistor Q5, and a set of MOS transistor Q1, MOS transistor Q3 and MOS transistor Q5 The electrodes are all connected to the voltage DC+, the emitters of MOS transistor Q0, MOS transistor Q2 and MOS transistor Q4 are all grounded, the collector of MOS transistor Q0 is connected to the emitter of MOS transistor Q1 and connected to the stator coil of the brushless DC motor The input terminal of L1 is connected, the collector of MOS transistor Q2 is connected with the emitter of MOS transistor Q3 and is connected with the input terminal of the stator coil L2 of the brushless DC motor, the collector of MOS transistor Q4 is connected with the emitter of MOS transistor Q5 The poles are connected and connected with the input end of the stator coil L3 of the brushless DC motor.

As a preference, the MCU microcontroller unit is connected with a run/stop button K1 and a forward/reverse rotation button K2. Operating the run/stop button K1 can control the start and stop of the brushless DC motor; operating the forward/reverse button K2 can control the brushless DC motor to run in forward or reverse mode.

The beneficial effects of the utility model are: neither RC filter circuit nor MOS drive circuit is needed, the feedback delay and control delay are reduced, the phase lag problem is effectively solved, and the forward and reverse rotation of the motor can be taken into account, so that the motor can be stably controlled The motor runs at high speed. The circuit is simple, the external components are greatly reduced, the stability and production yield are improved, and the cost is also reduced.

Description of drawings

Fig. 1 is a block diagram of circuit principle connection structure of the utility model.

Fig. 2 is a schematic diagram of a circuit connection structure of the utility model.

FIG. 3 is a schematic diagram of the correspondence between the rotor rotation angle of the brushless DC motor and the Hall value.

In the figure 1. MCU microcontroller unit, 2. MOS tube three-phase bridge unit, 3. Brushless DC motor, 4. Hall sensor, 5. Stator coil.

detailed description

The technical solutions of the present utility model will be further specifically described below through the embodiments and in conjunction with the accompanying drawings.

Embodiment: a kind of high-speed brushless DC motor control device of the present embodiment, as shown in Figure 1, comprises MCU microcontroller unit 1, MOS tube three-phase bridge unit 2 and three-phase bridge unit installed in brushless DC motor 3 stators A Hall sensor 4, the output end of the MCU microcontroller unit 1 is connected to the input end of the MOS tube three-phase bridge unit 2, and the output end of the MOS tube three-phase bridge unit 2 is respectively connected to the stator coil 5 of the brushless DC motor 3. The input terminals are connected, and the output terminals of the three Hall sensors 4 are respectively connected with the input terminals of the MCU microcontroller unit 1 .

The specific circuit is shown in Figure 2. The MCU microcontroller unit 1 includes a single-chip microcomputer U with a built-in MOS drive circuit. The single-chip microcomputer U has two timers. In this embodiment, the single-chip microcomputer U adopts the DRV91620 single-chip microcomputer. The single-chip microcomputer U has PWM0 pins, PWM1 Pin, PWM2 pin, PWM3 pin, PWM4 pin and PWM5 pin six output terminals, MOS tube three-phase bridge unit 2 includes MOS tube Q0, MOS tube Q1, MOS tube Q2, MOS tube Q3, MOS tube Q4 and MOS tube Q5, The collectors of MOS tube Q1, MOS tube Q3, and MOS tube Q5 are all connected to the voltage DC+, the emitters of MOS tube Q0, MOS tube Q2, and MOS tube Q4 are all grounded, and the PWM0 pin, PWM1 pin, PWM2 pin, PWM3 pin of the microcontroller U Pin, PWM4 pin and PWM5 pin are respectively connected to the bases of MOS tube Q0, MOS tube Q1, MOS tube Q2, MOS tube Q3, MOS tube Q4 and MOS tube Q5, the collector of MOS tube Q0 is connected to the emitter of MOS tube Q1 Connected and connected to the input end of the stator coil L1 of the brushless DC motor 3, the collector of the MOS transistor Q2 is connected to the emitter of the MOS transistor Q3 and connected to the input end of the stator coil L2, the collector of the MOS transistor Q4 is connected to the MOS transistor The emitter of Q5 is connected and connected to the input of stator coil L3. The single-chip microcomputer U is also connected with a run/stop button K1, a forward/reverse rotation button K2 and a reset circuit. Operating the run/stop button K1 can control the start and stop of the brushless DC motor; operating the forward/reverse button K2 can control the brushless DC motor to run in forward or reverse mode.

work process:

①Three Hall sensors 4 detect the position of the rotor of the brushless DC motor 3 in real time and send it to the single-chip microcomputer U, and the single-chip microcomputer U reads the current Hall value. A timer starts counting;

②When the Hall value jumps to the next Hall value, the microcontroller U reads the time Tn when the rotor passes through the nth Hall interval captured by the first timer. At this time, the rotor enters the n+1th Hall interval. Then it is divided into two steps: step a, return to step ①; step b, the second timer in the single-chip microcomputer U starts counting, and turns to step ③;

③Set the advance commutation time T0=(1/4)Tn when the rotor enters the n+2 Hall interval in advance in the single-chip microcomputer U;

④When the second timer reaches (3/4)Tn, the PWM signal output by the microcontroller U switches to the output phase corresponding to the n+2th Hall interval, and then processed by the MOS transistor three-phase bridge unit 2, respectively If the energization signal is output to the stator coil L1, stator coil L2 and stator coil L3 of the brushless DC motor 3, then the phase output of the stator coil in the n+2th Hall section of the rotor does not lag.

Among them, n cycles in the order of 1, 2, 3, 4, 5, 6 and back to 1. After various experiments, when m=4, the effect of solving the phase lag is more ideal. Of course, m can also be a natural number such as 3, 4, 5, 6 or 7, which can be changed and set according to different situations.

In order to explain clearly, the principle is explained below.

As shown in Figure 3, the Hall sensor feeds back six signal states of the rotor magnetic pole position: 001, 101, 100, 110, 010, 011, each signal state represents the angular range of the rotor operation, namely: 0 ~ 60° , 60～120°, 120～180°, 180～240°, 240～300°, 300～360° (0°), A, B, C, D, E, and F represent the intersection points of the six sectors respectively. For example: the time required for the rotor to run from point A to point B is T1, that is, the time for the rotor to rotate through the interval of 0° to 60°. By observing the back electromotive force phase diagram, it is observed that the phase lag is about 15°, and the time corresponding to the rotor running 15° is T0. The first timer inside the microcontroller captures the time when the Hall value jumps from 001 to 101 is T1, and from the observation that the phase lag is about 15°, T0=(1/4)T1 is set. Since the brushless DC motor can be considered to be running at a constant speed in two adjacent sectors, it is considered that from Hall The time T2=T1 when the value jumps from 101 to Hall value 100, correspondingly, the phase lag of the counter electromotive force is also about 15° at this time, then let the second timer inside the single-chip microcomputer start timing at point B, when the second timer counts At the moment (T1-T0), that is, when the rotor rotates (60°-15°), immediately switch to the stator winding output corresponding to the Hall value of 100, that is, switch in advance, then the phase of the 100 Hall interval output has no Hysteresis, to achieve the best torque output. In order to ensure that the next Hall value of 110 is also the best torque output, the first timer needs to measure the time T2 of the Hall value of 101, that is, the time from the Hall value of 101 to the Hall value of 100. At the moment of running in the 100 Hall interval (T2-T0), immediately switch to the stator winding output corresponding to the Hall value of 110, that is, switch in advance, then the phase of the 110 Hall interval output does not lag behind, ensuring the 110 Hall interval Optimum output corresponding to phase and torque. So cycle. It can be seen that when the rotor is running in the 101 section, it cuts to the phase output corresponding to the 100 section in advance of T0 time, and when the rotor runs in the 100 section, it switches to the phase output corresponding to the 110 section in advance of the T0 time, so it can be determined that the 100 section has run a complete 60 °, but it is 60° in the range from 105° to 165° when the actual Hall position angle is expressed. Of course, in the above specific description, the phase lag of 15° is just an example, in fact, the lag angle can be any angle smaller than 60°, and the phase correction is performed in this way.

The situation is the same when the brushless DC motor is running in reverse, except that the sector sequence is changed from 001, 101, 100, 110, 010, 011 in the forward rotation to 001, 011, 010, 110, 100, 101 in the reverse rotation .

The utility model adopts the MCU micro-controller to filter the Hall feedback signal, saves the peripheral RC filter circuit, and has stronger adaptability. In the environment with stronger interference to the Hall, it does not need to change the hardware circuit, and directly configures the MCU micro-control. The filter coefficient can be changed by using the register register to ensure that the Hall signal detection is correct, reduce the feedback delay and control delay, effectively solve the phase lag problem, and take into account the positive and negative rotation of the motor, so that the high-speed operation of the motor can be stably controlled. At the same time, the original MOS drive circuit that needs to be externally connected is also omitted, the circuit is simple, the external components are greatly reduced, the stability and production yield are improved, and the cost is also reduced.

Claims (4)

1. A high-speed brushless DC motor control device is characterized in that comprising MCU microcontroller unit (1), MOS tube three-phase bridge unit (2) and three Halls located in the brushless DC motor (3) stator Er sensor (4), the output end of MCU micro-controller unit (1) is connected with the input end of described MOS tube three-phase bridge unit (2), and the output end of MOS tube three-phase bridge unit (2) is respectively connected with no The input terminals of the stator coil (5) of the brush DC motor (3) are connected, and the output terminals of the three Hall sensors (4) are respectively connected with the input terminals of the MCU microcontroller unit (1). 2. A kind of high-speed brushless DC motor control device according to claim 1, it is characterized in that described MCU microcontroller unit (1) comprises the single-chip microcomputer U that is built-in MOS driving circuit, and single-chip microcomputer U has PWM0 pin, PWM1 Pin, PWM2 pin, PWM3 pin, PWM4 pin and PWM5 pin six output ends, described MOS tube three-phase bridge unit (2) has six MOS tubes, PWM0 pin, PWM1 pin, PWM2 pin, PWM3 pin of single-chip microcomputer U , PWM4 pin and PWM5 pin are respectively connected with the bases of six MOS tubes. 3. A high-speed brushless DC motor control device according to claim 2, characterized in that said MOS transistor three-phase bridge unit (2) includes MOS transistor Q0, MOS transistor Q1, MOS transistor Q2, and MOS transistor Q3 , MOS tube Q4 and MOS tube Q5, the collectors of MOS tube Q1, MOS tube Q3 and MOS tube Q5 are all connected to the voltage DC+, the emitters of MOS tube Q0, MOS tube Q2 and MOS tube Q4 are all grounded, and the MOS tube Q0’s The collector is connected to the emitter of the MOS transistor Q1 and connected to the input terminal of the stator coil L1 of the brushless DC motor (3), and the collector of the MOS transistor Q2 is connected to the emitter of the MOS transistor Q3 and connected to the The input end of the stator coil L2 of the brushless DC motor (3) is connected, the collector of the MOS transistor Q4 is connected with the emitter of the MOS transistor Q5 and connected with the input end of the stator coil L3 of the brushless DC motor (3) . 4. A high-speed brushless DC motor control device according to claim 1, 2 or 3, characterized in that the MCU microcontroller unit (1) is connected with a run/stop button K1 and a forward/reverse button K2.